Liquid fuel burner



May 13, 1947. J. H. JACKSON 2,420,598

LIQUID FUEL BURNER Filed Oct. 4, 1945 2 Sheets-Sheet l May 13, 1.947. J.H. JACKSON 2,420,593

LIQUID FUEL BURNER Filed Oct. 4, 1945 2 Sheets-Sheet 2 vg-9.5 5 @MMYLMZL Patented May 13, 1947 UNITED STATES PATENT sies 10 Claims.

This invention relates to liquid fuel burning apparatus, and inparticular to fuel oil burners.

One object of this invention is to provide a liquid fuel burner havingan improved arrangement of air ducts whereby a superior distribution ofthe air is brought about, thereby bringing about better combustion.

Another object is to provide a liquid fuel burner having a single airconduit divided into two ducts by a longitudinal vane or partition soarranged as to admit air on opposite sides of the air mixing chamber andthereby bring about improved air distribution and superior combustion.

Another object is to provide a liquid fuel burner as set forthl in thepreceding objects wherein the intake end of the air conduit issubstantially aligned with the fuel spray nozzle, thereby facilitatinginstallation and mounting.

Another object ls to provide a liquid fuel burner having an improvedhearth or retort wherein a flat zone is provided centrally thereof sothat the air emerging from the blast ring or central aperture ispermitted to move outwardly for a short distance prior to encounteringthe more strongly curved side walls of the retort, thereby givingimproved combustion andproviding a. layer of air between the inner wallsof the retort and the fuel spray so as to maintain the lower portion ofthe hearth relatively cool and permit the use of a metallic hearth orretort.

Another object is to provide a liquid fuel burner with a bowl-shapedhearth or retort having an annular flange surrounding it near the topthereof, thereby strengthening the retort and serving as a girdle toprotect lt against cracking due to rapid expansion under rapidly risingtempera tures.

Another object is to provide a liquid fuel burner having a bowl-shapedhearth or retort preferably of metallic material, and having aninsulating coating on the outside thereof so as to prevent undue loss ofheat by conduction and radiation through the retort.

Another object is to provide an improved air supply device for fuelburners consisting of a single air supply conduit curving around the airmixing chamber and divided into two ducts by a longitudinal vane orpartition so arranged as to admit air on opposite sldesof the air-mixingchamber and thereby bring about improved air distribution and superiorcombustion.

Another object is to provide a fuel burner having an improved auxiliaryair tube associated with the fuel supply nozzle and having improvedmeans for adjusting the ilow of air therethrough.

Other objects and advantages will become apparent during the course ofthe following description of the accompanying drawings, wherein:

Figure 1 is a top plan view of a liquid fuel burner according to thepreferred form of the invention, with the top partially broken away todisclose portions of the interior;

Figure 2 is a longitudinal section through the liquid fuel burner ofFigure 1, taken along the broken line 2--2 therein;

Figure 3 is a. cross-section through the airmixing chamber taken alongthe line 3--3 in Figure 1;

Figure .4 is a cross-section through the air lintake conduit, takenalong the line 4-4 in Fig-i `ure 2: i

Figure 5 is a cross-section through the auxillary air tube taken alongthe line 5-5 in Figure 2; and 4 Figure 6 is a top plan view of avmodified form of liquid fuel burner with thetop partially broken away todisclose a portion of the interior.

Referring to the drawings in detail, Figure 1 shows a preferred form ofthe liquid fuel burner of this invention as including a casing l0 havingan air supply conduit il with an intake portion it Whose axis issubstantially aligned with a liquid fuel spray nozzle i3. The air supplycon duit l l is provided with a central vane or parti tion it (Figure 4)dividing it into two ducts l5 and i6. The end of the partition I4terminates in an inwardly bent portion Il' serving as an inwardly-directed baille and curved to prevent direct collision betweenthe air stream entering the air-mixing chamber iii through the duct land the air stream entering through, the duet l5, and bring about asmooth blending thereof. The bent portion Il also provides a full widthoi the air duct l5 at its discharge opening le and prevents constrictionthereof. IThe casing I El is provided with a partition 2! forming ineffect a continuation of the wall 2 of the conduit l l and having. abent portion 2i? serving as an inwardlydirected baffle in a. mannersimilar to the bent portion I1 on the end of the partition I4. The bentportion 22 likewise serves to prevent, direct collision between theyairstreams and brings about a smooth blending thereof. The intake endI2 of the conduit II is provided with an internal rib 23 to serve as anabutment for a pipe telescoped into the vestibule 24 thereof andconveying air from the blower of the power plant (not shown). The intakeportion I2 is also provided with dampers 25 and 26 within the ducts I5and I6 and secured to bolts 21 and 28 respectively. The bolts 21 and 28are provided with spiral springs 29 for urging the dampers 25 and V2litoward their open positions. Adjusting thumb screws 30 and 3| for thedampers 25 and 26 are threaded through the side walls of the casing II(Figure 1), and engage the dampers 25 and 26 respectively. By turningthe thumb screws 38 and 3I inwardly, the dampers 25 and 26 are caused tomove in directions tending to close the ducts I and I6, and thisadjustment can be xed by means of lock nuts 32. By adjusting the thumbscrews 30 and 3i, and consequently the dampers 25 and 26, the airentering the vestibule 24 is proportioned between the ducts I5 and I6 inany desired amount, thereby controlling the relative amounts of airentering the air mixing chamber I8 through the discharge openings I9 and33 of the ducts I5 and I6 respectively, and the air-mixing chamber I8 isthereby supplied with streams of air from diametrically oppositelocations.

The fuel spray nozzle I3 is mounted substantially centrally in theair-mixing chamber I8 and has a spray head 34 threaded into the upperend of a fuel supply stem 35, the lower end of which (Figure 3) isthreaded as at 36 and passed through a bore 31 in the bottom wall 38 ofthe casing I0. Nuts 39 and 40 secured on opposite sides of the bottomwall 38 hold the stem 35 rigidly in position. The stem 35 at its lowerend is internally threaded to receive the threaded end 4I 0f an elbow 42having a threaded union 43 connecting it to a liquid fuel supply pipe 44(Figure 2). Surrounding the stem 35 and spaced from it by thespider-like centering member 45 (Figure'l) is an auxiliary air tube 46having its upper end immediately below the level of the spray head 34and its lower end resting upon the bottom wall 38. The lower portion ofthe auxiliary air tube 46 is provided with ports 41 distributed aroundthe periphery thereof and cooperating with an air adjusting sleeve 48having similar ports 49 therein. A set screw 50 threaded into a boss 5Ion the air adjusting sleeve 48 provides for an adjustment of the airpassing through the cooperating ports 41 and 49. The sleeve 48, whenrotated to a, position where the air passages provided by thecooperating ports 41 and 49 are of suitable width, is locked in positionby tightening the set screw 50.

The bottom wall 38 is provided with bosses 52 on opposite sides of thebore 31, these being internally threaded as at 53 to receive thethreaded ends 54 of ignition plugs 55 having insulators 56 and terminals51 attached to central electrodes 58 passing into the air mixing chamberI8 through insulating tubes 59. The electrodes 58 are bent at rightangles so that their ends 66 form a spark gap (Figure l). To theterminals 51 are connected wire cables 6I which pass through insulatingtubes 62 (Figure 2) mounted in bores 63 in a downwardly extendingbracket 64 forming a part of the casing IU. The latter is supported uponleveling studs 65 (Figures 2 and 4) threaded into the bores 66 in thecasing IIJ and secured thereto by the lock nuts 61. Threaded upon thelower ends of the studs 65 are conical supports 68 locked in position bythe lock nuts 69. The supports 68 may thus be moved upwardly ordownwardly upon the studs 65 to level the apparatus and to adjust it toirregularities in the floor, grates or other portion of the furnace uponwhich the device rests.

The top of the casing I0 is provided with a corneal flange 10 providinga circular outlet 1I around the spray nozzle I3. Resting' upon theflange 10 is a conical adapter ring 12 having a stepped portion 13 ofapproximately the same thickness as the flange 1I! so that the innersurfaces of the flange 10 and the adapter 12 form a. substantiallycontinuous cone. Resting upon the upper annular shoulder 14 of theadapter 12 is a bowl-shaped hearth or retort 15 having a relatively iiator shallowly curved annular zone 18 extending approximately to theboundary circle 11 from the edge circle 16 of the aperture in the centerof the hearth 15. Beyond the boundary circle 11 of the iiat zone 16, thehearth 15 is provided with a more strongly curved side wall 19.

The hearth 15 near its upper edge 80 is provided with an integralannular flange 8I. The latter serves as a strengthening member or girdleto prevent the hearth 15 from cracking under the high and uneventemperatures generated by the combustion within the hearth 15. Theannular flange 8I also vserves as a support for the struc- .tureconnecting the hearth 15 to the side walls of the furnace or rebox inwhich the apparatus is installed. The outer wall 82 of the hearth 15 issurrounded by an insulating layer 83 of asbestos or other fire resistingmaterial. The insulating layer 83 prevents the escape and loss of heatby conduction through the hearth 15, thereby conserving fuel.

The modification shown in Figure 6 is generally similar to the preferredform shown in Figure 1 except that the intake portion II2 of the airsupply conduit'l II is offset relatively to the spray nozzle II3, sothat the air duct IIS is substantially straight and the air duct I I5 isapproximately in the form of a letter J. In the principal form of theinvention (Figure 1), the air duct I5 is approximately in the form of aquestion mark, (2), due to the substantial alignment of the lntakeportion I2 with the spray nozzle I3. The remaining features of themodification of Figure 6 are substantially the same as those of the formshown in Figure 1 and are similarly designated by reference numerals.

In the operation of the invention, the vestibule 24 is connected to theconduit from the blower associated with the usual power plant (notshown) and a stream of air supplied thereto. The air enters thevestibule 24 and is divided by the partition or vane I4 into twostreams. One stream passes through the duct I6 directly into the airmixing chamber by way of the discharge opening 33, whereas the otherstream passes through the air duct I5 along a path shaped substantiallylike a question mark or sickle and enters the air mixing chamber I8through the intake opening I9 on the opposite side thereof. The

end portions I1 and 22 serve as bailles to prevent the two air streamsfrom colliding abruptly and causes them to blend evenly so as toeliminate dead air spots and insure even combustion in the hearth 15.

The liquid fuel such as fuel oil, is supplied through the pipe IIII tothe spray nozzle I3 and ignited by a spark passing between the electredeends 80 (Figure 1). The adjusting ring IIB is turned relatively to theauxiliary air tube 46 so that a proper amount of air passes through theports 41 and 49. Meanwhile, the proportionate amounts of air passingthrough the ducts I 5 and I6 have been adjusted by changing the positionof the dampers 25 and 26 by means of the thumb screws 3|] and 3|(Figure 1) so that the correct air mixture is obtained in the hearthwithout dead air spots or areas. The air passing upward from the outlet'II throughthe circle 3d shoots outward over the iiat zone 5E beforeencountering the curved inner wall i9 of the hearth 15, therebyproviding a, cushion of air in the vicinity of the zone 'I6 and lowerportions of the hearth l5. By this means, combustion takes place largelyin the upper portions of the hearth 'l5 so that the lower portionsthereof are relatively cool. This construction enables a metallic hearthto be employed, for example cast ironfthereby eliminating the fragilityof hearths of refractory materials, such as re clay. The latter arediilicult to ship without breakage and also frequently fail during use,ythe resulting cracks admitting air and interfering with satisfactorycombustion.

While I have shown and described my invention in detail, it is to beunderstood that the same is to be limited only by the appended claims,for many changes may be made Without departing from the spirit and scopeof my invention.

What I claim is:

1. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a. liquid fuel spray nozzle mounted in said chamber anddirected toward the outlet thereof, an air supply conduit connected tosaid chamber, said conduit having an internal longitudinal partitiontherein dividing said conduit into outer and inner air supply ducts,said ducts discharging into said chamber at locations remote from =eachother and on opposite sides of said outlet and means in said conduit forconstricting the flow` of air through one of said ducts whereby toproportion the air passing through said ducts into said chamber.

2. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a liquid fuel spray nozzle mounted in said chamber anddirected toward the' outlet thereof, an air supply conduit connected tosaid chamber, said conduit having an internal longitudinal partitiontherein dividing said conduit ,into outer and inner air supply ducts,one of said ducts extending around said chamber and said ductsdischarging into said chamber at locations remote from each other and onopposite sides of said outlet and means in said conduit for ccnstrictingthe flow of air through one of said ducts whereby to proportion the airpassing through said ducts into said chamber.

3. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a liquid fuel spray nozzle mounted in said chamber anddirected toward the outlet thereof, an air supply conduit connected tosaid chamber, said conduit having an internal longitudinal partitiontherein dividing said conduit into outer and inner air supply ducts,said ducts discharging into said chamber at locations remote from eachother and on opposite sides of said outlet, and a damper in one of saidair ducts arranged to constrict the flow of air therethrough forproportioning the distribution. of the air between said ducts.

' sectional area thereof whereby to vary the proportionate amounts ofducts to said chamber.

5. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a liquid fuel spray nozzle mounted in4 said chamber anddirected toward the outlet thereof, an air supply conduit connected tosaid chamber, said conduit having an internal `longitudinal partitiontherein dividing said conduit into outer and inner airl supply ducts,said ducts discharging into said chamber at locations remote from eachother and on opposite sides of said outlet, and an inwardly-directedbaille at the end of said parti tion whereby to prevent direct collisionbetween and evenly blend the air streams discharged from said outer andinner ducts into said chamber.

6. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a liquid fuel spray nozzle mounted in said chamber anddirected toward the outlet thereof, an air supply conduit connected tosaid chamber, said conduit having an internal longitudinal partitiontherein air distributed by said ldividing said conduit into outer andinner air supply ducts, said ducts discharging into said chamber atlocations remote from each other and on opposite sides of said outlet,and `an inwardly-directed baille at the end of said partition and asecond inwardly-directed baille at the location of entry of said innerair duct into said chamber whereby to prevent direct collision betweenand evenly blend the air streams discharged from said outer and innerducts into said chamber.

7. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a liquid fuel spray nozzle mounted in said chamber anddirected toward the outlet thereof, and an air 4 supply conduit assemblyconnected to said chamber, said conduit assembly having a plurality ofair supply ducts discharging into said chamber at remotely separatedlocations on opposite sides of said outlet, one of said ducts beingapproxi mately sickle-shaped and partially encircling said chamber.

8. In a liquid fuel burner, a casing having therein an air chamber withan outlet, a liquid fuel spray nozzle mounted in said chamber anddirected toward the outlet thereof, an air supply conduit assemblyconnected to said chamber, said conduit assembly having a. plurality ofair supply ducts discharging into said chamber at remotely separatedlocations on opposite sides of said outlet, one of said ducts beingapproxiu mately sickle-shaped and partially encircling said chamber, andair proportioning mechanism extending into said ducts for varying theproportionate amounts or air distributed by said ducts to said chamber.

9. An air supply casing for fuel burners com-a prising a housing havingtherein an air chamber with an outlet, and an air supply conduitconnected to said chamber, said conduit having an internal longitudinalpartition therein dividing asesores said conduit into outer and innersupply ducts, one of said ducts partially encircling said chamber andsaid ducts discharging into said chamber at locations remote from and onopposite sides of said outlet.

l0. An, air supply casing for fuel burners comprising a housing havingtherein an air chamber with an outlet, an air supply conduit connectedto said chamber, said conduit having an internal longitudinal partitiontherein dividing said conduit into outer and inner supply ducts, one ofsaisi. ducts partially encircling said chamber and said ductsdischarging into said chamber at locations remote from and on oppositesides of said outlet, and valve means in said conduit arranged to varythe cross-sectional area of each duct for proportionately distributingthe air supplied thereto between said ducts.

JAMES H. JACKSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number UNITED STATES PATENTS Name Date Ogilvy May 15, 1928 Fletcher June19, 1928 Sundstrand Feb. 18, 1930 Jackson Nov. 28, 1939 Jackson Jan. 13,1942 Donley et al Dec. 30, 1930 Ewing May 4, 1926 Meyers Feb. 5, 1924Tyrrell May 20, 1924 White Mar. 2, 1915 Reid June 7, 1921 Kerrick June2, 1942 Robinson Oct. 30, 1888 Udesen Sept. 1, 1936 Couch Mar. 31, 1925Ross Dec. 1, 1936

